function drawBackBtn(scene, callback) {
    const layerW = 60;
    const layerH = 60;
    const btnW = 48;
    const btnH = 48;
    const btnX = SizePw + btnW / 2;
    const btnY = SizePh + btnH / 2;
    const layerX = SizePw - (layerW - btnW) / 2;
    const layerY = SizePh - (layerH - btnH) / 2;

    const btnLayer = new egret.Shape();
    btnLayer.graphics.beginFill(ColorBlack, 0.1);
    btnLayer.graphics.drawRoundRect(layerX, layerY, layerW, layerH, layerW, layerH);
    scene.addChildAt(btnLayer, 1);

    const btnBack = createBitmapByName("button_back_png");
    btnBack.width = btnW;
    btnBack.height = btnH;
    btnBack.anchorOffsetX = btnW / 2;
    btnBack.anchorOffsetY = btnH / 2;
    btnBack.x = btnX;
    btnBack.y = btnY;
    btnBack.touchEnabled = true;
    scene.addChildAt(btnBack, scene.numChildren + 1000);
    btnBack.addEventListener(egret.TouchEvent.TOUCH_BEGIN, (evt: egret.TouchEvent) => {
        btnBack.rotation = -30;
    }, scene);
    btnBack.addEventListener(egret.TouchEvent.TOUCH_END, (evt: egret.TouchEvent) => {
        btnBack.rotation = 0;
        typeof callback === 'function' && callback.call(scene);
    }, scene);
    btnBack.addEventListener(egret.TouchEvent.TOUCH_RELEASE_OUTSIDE, (evt: egret.TouchEvent) => {
        btnBack.rotation = 0;
    }, scene);
    return btnBack;
}
